The six unreactive elements, of which Argon is a member, as a class are referred to as the "Noble" or Inert Gases, found on the rightmost column of the Periodic Table. As elements, none are created through chemical reactions, but may be isolated through such reactions. As difficult as it is to get them to react, by 1962 a British-Canadian chemist Neil Bartlett was able to synthesize a new compound composed of the Nobel Gases Xenon and Fluorine and the metal Platinum, into xenon fluororoplatinate (XePtF6). This first synthesis with Noble Gases led other chemists to synthesize xenon difluoride (XeF2) and krypton tetrafluoride (KrF4.) In 2000, the first compound containing Argon was synthesized, Argon Fluorohydride (ArFH).
The New Intelligent Man's Guide to Science, pg. 224, I. Asimov, 1965.
It is called an unreactive element because it has a stable electronic configuration and does not share its electrons with other atoms.
Argon, discovered in 1894, makes up 0.93% of the earth's atmosphere, which makes it the third most abundant gas. It is a byproduct of the production of oxygen and nitrogen.
Argon is used to fill incandescent and fluorescent light bulbs to prevent oxygen from corroding the hot filament. It is also used in arc welding, growing semiconductor crystals, and "processes that require shielding from other atmospheric gases."
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